The GMB union has expressed its disappointment as staff had signed up to Mr Mochrie’s long-term vision for the trust.

Mr Mochrie said: “I am and will remain immensely proud of the real progress we have made at SECAmb during the past 18 months. I know that there is still more to do but as a trust we have already made significant steps forward and I know I will be leaving the Trust with a strong leadership team who are committed to making this happen.

“I have not taken this decision lightly and have greatly enjoyed my time as chief executive of SECAmb. While the process to recruit my replacement is under way, I remain fully committed to SECAmb and look forward to working hard with my colleagues and the wider NHS on providing the best care possible to our patients.”

David Astley, SECAmb chair, said: “While I was disappointed to hear of Daren’s decision, I am pleased that he has the opportunity to further his career by leading North West Ambulance Service from next spring and we wish him every success.

“The fact that Daren has been recruited to such a major role reflects the high regard in which he is held nationally and is testament to the improvements he and everyone at SECAmb has made since he joined the trust.

“Daren has laid the foundations for our continued development and to further improve our services to the public. I know that he will continue this work, alongside our strong executive team, during his notice period.”

“The fact that there has been any kind of services within SECAmb is due to the dedication and professionalism of the staff on the ground. The commitment of the paramedics, call handlers and ambulance staff is beyond reproach. The same cannot be said about senior management of this organisation.

“Mr Mochrie’s tenure represents a missed opportunity to right the wrongs of the past within this trust, and his stated reason for leaving is very disappointing if not insulting to the hard working staff of SECAmb.”